What Series Questions Test
- Number series — differences, squares, mixed rules
- Letter series — alphabet gaps and cycles
- Alphanumeric series — combined letter-number terms
- Series completion and wrong-term spotting
Question bank coverage by sub-pattern
How Series Appears in SSC CGL
Series is part of the General Intelligence & Reasoning section (25% of the SSC CGL syllabus). See the full SSC CGL Tier-I breakdown.
Series Solved Examples for SSC CGL
12 exam-pattern series questions from the practice bank, each with a full solution.
What is the next number in the following series: 1, 4, 9, 16, ?
- A.20
- B.25Correct
- C.30
- D.36
Solution
The series consists of squares of consecutive natural numbers: 1^2 = 1, 2^2 = 4, 3^2 = 9, 4^2 = 16, 5^2 = 25.
Find the next term: 2, 3, 5, 7, 11, 13, ?
- A.15
- B.17Correct
- C.19
- D.14
Solution
This is the series of prime numbers. 2, 3, 5, 7, 11, 13 — the next prime number is 17.
Find the missing number: 4, 9, 25, 49, 121, ?
- A.144
- B.169Correct
- C.196
- D.225
Solution
These are squares of prime numbers: 2^2=4, 3^2=9, 5^2=25, 7^2=49, 11^2=121. The next prime is 13, so 13^2=169.
Select the option that represents the letters that, when sequentially placed from left to right in the blanks below, will complete the letter series. M_ _ KS _ ON _ SMO _ K _ _ _ NKS
- A.ONMNKOMSCorrect
- B.ONMKNSMO
- C.ONMMMMMO
- D.NMOKNSMO
Solution
The series is: MONKS, MONKS, MONKS, MONKS. Therefore, the missing letters are ONMNKOMS.
Which of the following terms will replace the question mark (?) in the given series? CM, EP, GO, IS, KQ, MV, OS, ?
- A.PY
- B.QYCorrect
- C.QZ
- D.QX
Solution
The pattern is: +2, +3. C+2=E, M+3=P. E+2=G, P+3=S. G+2=I, O+3=R. I+2=K, S+3=V. K+2=M, Q+3=T. M+2=O, V+3=Y. O+2=Q, S+3=V. Therefore, the next term is QY.
Select the option that represents the letters that, when placed from left to right in the blanks below, will complete the letter series. _TM_PT_R__MRP__R
- A.MPTRMTT
- B.PRMPTTM
- C.PMTRRMT
- D.MTPRTMRCorrect
Solution
The series is M T M P T R M R P T M R. The pattern is MTM, PTR, MRP, TRM, PR.
Select the letter that can replace the question mark (?) in the following series. O, B, L, C, I, D, F, E ?
- A.K
- B.CCorrect
- C.H
- D.N
Solution
The pattern is -3, +1, -3, +1. O-3=L, L-3=I, I-3=F, F-3=C. B+1=C, C+1=D, D+1=E.
Select the number that can replace the question mark (?) in the following series. 87, 89, 92, 97, 104, 115, ?, 145
- A.125
- B.128Correct
- C.133
- D.132
Solution
The differences between the numbers are 2, 3, 5, 7, 11, 13, 17. 87+2=89, 89+3=92, 92+5=97, 97+7=104, 104+11=115, 115+13=128, 128+17=145.
Which of the four options will replace the question mark (?) in the following series? UE 88, VG 84, WI 80, XK76, ?
- A.ZM72
- B.ZN71
- C.YN73
- D.YM72Correct
Solution
The pattern is +1 for letters and -4 for numbers. X+1=Y, K+2=M, 76-4=72
Which of the following terms will replace the question mark (?) in the given series? YZUW, ?, QTQU, MQOT, INMS
- A.UWSVCorrect
- B.UWVS
- C.USWV
- D.WUSV
Solution
The series follows a pattern of decreasing letters. YZUW -> UWSV -> QTQU -> MQOT -> INMS
Select the letter-cluster that can replace the question mark (?) in the following series. KQG, JTK, HXO, ECS ?
- A.BIV
- B.AIWCorrect
- C.AHW
- D.BIX
Solution
The pattern involves subtracting 1, 2, and 3 from the first letters, adding 3, 4, and 5 to the second letters, and adding 4 to the third letters. Applying this pattern, the next cluster is AIW.
Find the missing term in the series: QPO, NML, KJI, ?
- A.HGFCorrect
- B.FED
- C.GFE
- D.HGE
Solution
Each group consists of three consecutive letters in reverse order. QPO: Q(17),P(16),O(15). NML: N(14),M(13),L(12). KJI: K(11),J(10),I(9). Next: H(8),G(7),F(6) = HGF.
Series — Frequently Asked Questions
How are letter series decoded quickly?
Convert letters to positions (A=1 … Z=26) and treat it as a number series. Gaps of +2/+3, alternating jumps and reversals become obvious as numbers.
What distinguishes SSC series questions from banking ones?
SSC leans on letter and figure series alongside numeric ones, while banking papers focus on numeric series. Practising all three families covers both patterns.
How many Series practice questions does Parikshala have for SSC CGL?
77 exam-pattern Series questions for SSC CGL Reasoning, each with a step-by-step solution. Practice is free — no sign-up needed to start.